In recent years, the display technology has developed rapidly, and the flat panel display device has replaced the bulky CRT display device and has become increasingly popular in people's daily life. At present, the commonly used flat display device includes a liquid crystal display (LCD) device and an organic light emitting diode (OLED) display device. The flat display device has the characteristics of small size, low power consumption, no radiation, etc., and occupies a dominant position in the current flat display device market.
Since the OLED technology is not yet mature, the current mainstream flat display device is still LCD. According to the LCD display type, it can be divided into: TN type, VA type, IPS type and FFS type. As far as the viewing angle is concerned, the VA, IPS and FFS types are better than the TN type, and a TN-type display screen with a narrow viewing angle is mainly used for NB and other mobile office products. In the existing display products, the viewing angle is fixed and single, and cannot meet the requirements of different application places and viewing preferences. Therefore, it is necessary to provide a display device with a switchable viewing angle.
In the MVA LCD display device, the large viewing angle image is easy to produce a large viewing angle light leakage and wash out phenomenon due to uneven cell gaps. A lot of solutions are proposed in the industry to improve this large viewing angle display effect, such as multi-domain, 1G1D coupling and 2D1G technologies. In the 2D1G technology, it is possible to provide signals for the Main pixels and the Sub pixels, respectively, which leads to the possibility of improving the large viewing angle display effect by using different gamma curves.
However, the 2D1G technology will bring the problem of decrease of a penetration rate, and thus the display effect and the penetration rate of an image under the large viewing angle cannot be taken into account at the same time.
For example, Chinese patent application CN201510344787.8 describes a method for improving an LCD large viewing angle display effect. This method combines the LCS transformations of time and space signal processing to achieve a good large viewing angle improvement effect in 4 domains. However, due to the reasons that the drive frequency is not high enough (120 to 240 Hz), the liquid crystal response is not fast enough, and the gray-scale difference between two frames during switching is too large, and so on, the flicker phenomenon is sometimes observed in the picture.
During the design of the time and space mixed 4 domains to alleviate the color shift at a large viewing angle, there are two problems that cannot be avoided:
(1) the problem that the decrease of a spatial resolution leads to the loss of the resolution in the details of the picture;
(2) the problem that the decrease of a time resolution leads to the flicker in switching of light and dark pictures.
In actual situation, if the brightness difference between two frames of one same sub-pixel is too large, the possibility of generating a flicker phenomenon will be increased. Considering that the general distribution form of H/L signals is generally roughly like the contour of the curve as shown in FIG. 3, the maximum gray-scale difference position of H/L is in the vicinity of 150 to 170 gray scales, while the maximum brightness difference position has a slightly higher gray scale than the maximum gray-scale difference position.
Therefore, in order to solve the existing technical problem that the display effect and the penetration rate of the image under the large viewing angle in the MVA LCD display device cannot be taken into account at the same time, the technical solution of the present disclosure is proposed.